Oxygen sensor for liquid metal and manufacturing method thereof

Abstract

The invention provides an oxygen sensor for liquid metal and a manufacturing method thereof. The oxygen sensor for the liquid metal comprises a protective shell and a sensing structure, the protective shell comprises a first shell and a second shell which are detachably connected; the sensing structure comprises a solid electrolyte oxygen probe and a sealing assembly, the sealing assembly is arranged in the first channel, one part of the solid electrolyte oxygen probe is located in the first channel, and the other part of the solid electrolyte oxygen probe is located in the second channel and the liquid metal contact hole. The first shell and the second shell are detachably connected, so that the solid electrolyte oxygen probe can be conveniently replaced, the reusability is improved, and the cost is reduced. The sealing assembly divides the containing channel into two channels, the sealing assembly isolates external air, the air is prevented from making contact with the liquid lead bismuth, and the sealing performance is effectively improved when the concentration of the dissolved oxygen in the liquid lead bismuth is detected.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of oxygen sensors, and in particular to an oxygen sensor for liquid metal and a manufacturing method thereof. BACKGROUND

[0002] Liquid lead bismuth (LBE) has excellent neutron characteristics, such as high neutron yield and low capture cross section, and other thermophysical properties (such as good thermal conductivity, low melting point, high boiling point, low saturated vapor pressure and low chemical activity), making it an ideal choice for lead-based fast reactor coolant and accelerator driven system (ADS) fissile target. Liquid lead bismuth not only enables higher power density of the reactor and supports miniaturization of the reactor, but also has high radiation resistance and the advantage of not reacting violently with air and water.

[0003] Liquid lead bismuth also faces several technical challenges in nuclear reactor applications, particularly its corrosiveness to iron-based structural materials. Oxygen is considered to be an ideal corrosion inhibitor in liquid lead bismuth, which can effectively reduce the corrosion rate by forming a stable oxide protective layer (such as Fe3O4 protective layer) on the surface of the structural material. Studies have shown that the oxygen concentration in liquid lead bismuth must be strictly controlled to avoid the formation of lead oxide precipitates, while also ensuring sufficient oxygen concentration to form a Fe3O4 protective layer. Lead oxide is the most stable oxide in lead bismuth alloy, and excess dissolved oxygen in liquid lead bismuth not only leads to the precipitation of lead oxide, causing pipe blockage and heat transfer performance degradation, but also can cause serious reactor accidents. Therefore, the upper limit of the dissolved oxygen concentration in liquid lead bismuth is determined by the solubility of lead oxide, and the lower limit is determined by the oxygen concentration required for the formation of Fe3O4 on the surface of the structural material. Therefore, how to effectively control the dissolved oxygen concentration in liquid lead bismuth is the key to ensuring the long-term safe and stable operation of the reactor.

[0004] However, most oxygen sensors with high precision, wide applicable temperature range and strong stability use air as a reference electrode, which has very high sealing requirements, especially in the part where the ceramic probe contacts the metal. If air leaks into the liquid lead bismuth, not only will the oxygen control fail, but also a large amount of solid lead oxide compounds will be generated in the liquid lead bismuth, causing reactor accidents. There are two sealing forms of traditional oxygen sensors as follows: First: using a simple graphite gasket for sealing, the sealing performance of the oxygen sensor is poor; Second: using a welding method of ceramic and stainless steel shell for sealing, the manufacturing process of the oxygen sensor is complex, and the equipment requirements and cost of assembling the oxygen sensor are high. Moreover, since the solid electrolyte ceramic in the oxygen sensor is a consumable and is easily damaged, it has a high replacement frequency. In this sealing method, the ceramic and stainless steel are in a welded structure, and once the ceramic fails, the entire oxygen sensor cannot be used because the ceramic cannot be replaced alone, resulting in high cost. SUMMARY

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art, and to provide an oxygen sensor for liquid metal and a manufacturing method thereof, which effectively improves the sealing performance and reduces the cost.

[0006] The purpose of the present disclosure is achieved by the following technical solutions: An oxygen sensor for liquid metal comprises a protective shell and a sensing structure; the protective shell is used for being mounted on an oxygen concentration electric measurement support, and has a containing channel and a liquid metal contact hole which are in communication with each other; the sensing structure comprises a solid electrolyte oxygen probe and a sealing assembly; the solid electrolyte oxygen probe is arranged in the containing channel, and a part of the solid electrolyte oxygen probe corresponds to the liquid metal contact hole, so as to contact liquid lead bismuth through the liquid metal contact hole; the solid electrolyte oxygen probe is used for being electrically connected with an electric measurement reference end of the oxygen concentration electric measurement support; and the sealing assembly is connected with the solid electrolyte oxygen probe. The protective shell comprises a first shell and a second shell which are detachably connected; the first shell has a first channel; the second shell has a second channel and the liquid metal contact hole which are in communication with each other; and the first channel and the second channel jointly form the containing channel; the sealing assembly is arranged in the first channel and abuts against an inner wall of the first shell, so as to seal the containing channel; a part of the solid electrolyte oxygen probe is located in the first channel, and another part of the solid electrolyte oxygen probe is located in the second channel and the liquid metal contact hole.

[0007] In one of the embodiments, the sealing assembly comprises at least two sealing members which are connected with the solid electrolyte oxygen probe in sequence and are spaced apart along the containing channel; and each of the sealing members abuts against an inner wall of the containing channel.

[0008] In one of the embodiments, the sealing member comprises a first high-temperature-resistant fluororubber ring, an iron ring and a second high-temperature-resistant fluororubber ring which are arranged in layers; the first high-temperature-resistant fluororubber ring, the iron ring and the second high-temperature-resistant fluororubber ring are all sleeved on the solid electrolyte oxygen probe; the high-temperature-resistant temperature of the first high-temperature-resistant fluororubber ring and the second high-temperature-resistant fluororubber ring is greater than or equal to 400 DEG C; and / or, the oxygen sensor for liquid metal further comprises a heat dissipation fin which is connected with an outer wall of the protective shell; and / or, the sealing member is located at an end of the solid electrolyte oxygen probe which is away from the liquid metal contact hole.

[0009] In one of the embodiments, the sealing member is located at an end of the solid electrolyte oxygen probe which is away from the liquid metal contact hole.

[0010] In one of the embodiments, the protective shell further comprises a sealing pipe connected with the first shell, the sealing pipe is located in the first channel, the inside of the sealing pipe is communicated with the first channel, at least one of the sealing members is arranged in the sealing pipe, and the sealing pipe is abutted by at least one of the sealing members at one end close to the liquid metal contact hole.

[0011] In one of the embodiments, the sealing pipe comprises a pipe body and a limiting pipe, the pipe body is connected with the inner wall of the first channel, the limiting pipe is connected with the inner wall of the pipe body, and at least one of the sealing members is abutted by the limiting pipe at one end close to the liquid metal contact hole.

[0012] In one of the embodiments, the sensing structure further comprises a fastening nut screwed with the protective shell, the fastening nut is arranged in the accommodating channel, the fastening nut corresponds to the liquid metal contact hole, the fastening nut is abutted by the solid electrolyte oxygen probe, and / or the opening area of the liquid metal contact hole is smaller than the axial cross-sectional area of the solid electrolyte oxygen probe at the liquid metal contact hole.

[0013] In one of the embodiments, the liquid metal oxygen sensor further comprises an electrode lead wire, a mounting flange and a flange belt, the electrode lead wire is arranged in the accommodating channel, the electrode lead wire is connected with the solid electrolyte oxygen probe and the flange belt respectively, the mounting flange is sleeved on the outer wall of the protective shell, part of the flange belt is clamped in the accommodating channel, the mounting flange and the flange belt are located at one end of the protective shell away from the liquid metal contact hole, the mounting flange and the flange belt are used for being fixed on an oxygen concentration electric measurement support, and the flange belt is further used for being electrically connected with an electric measurement reference end of the oxygen concentration electric measurement support.

[0014] In one of the embodiments, the protective shell is provided with a gas permeable hole communicated with the accommodating channel, and the gas permeable hole is located at one end of the protective shell away from the liquid metal contact hole.

[0015] In one of the embodiments, 5g to 20g of LSCF powder or LSM powder is filled in the inner cavity of the solid electrolyte oxygen probe, and / or a Pt layer with a thickness of 1cm to 3cm is formed on the inner cavity wall of the solid electrolyte oxygen probe by electroplating.

[0016] A manufacturing method of a liquid metal oxygen sensor, comprising: providing a solid electrolyte oxygen probe; forming a reaction catalyst in the inner cavity of the detection end of the solid electrolyte oxygen probe; arranging a sealing assembly in the first channel of the first shell to seal the accommodating channel; The solid electrolyte oxygen probe is inserted into the first channel and connected to the sealing assembly; The second housing is detachably connected to the first housing, and the portion of the solid electrolyte oxygen probe located outside the first housing is inserted into the second housing, such that a portion of the solid electrolyte oxygen probe is located in the first channel, and the other portion of the solid electrolyte oxygen probe is located in the second channel and the liquid metal contact hole. Insert the fastening nut into the second housing and press the end of the solid electrolyte oxygen probe adjacent to the liquid metal contact hole; The electrode wire is inserted into the inner cavity of the solid electrolyte oxygen probe through the first channel, and one end of the electrode wire is inserted into the inner cavity of the solid electrolyte oxygen probe at the detection end.

[0017] Compared with the prior art, this disclosure has at least the following advantages: The aforementioned oxygen sensor for liquid metal features a detachable connection between the first and second housings, meaning the protective outer shell is removable. This allows for replacement of the solid electrolyte oxygen probe, improving the reusability of the sensor and reducing costs. A sealing assembly is added between the solid electrolyte oxygen probe and the protective shell. This assembly divides the accommodating channel into two channels. The channel near the liquid metal contact hole houses the solid electrolyte oxygen probe, forming a reference electrode for easy contact with the liquid metal. The channel near the liquid metal contact hole serves as a conductive part, facilitating the transmission of the electrical signal sensed by the solid electrolyte oxygen probe to the electrical reference end of the oxygen concentration measuring bracket. This allows for accurate measurement of the oxygen concentration within the liquid metal. Furthermore, the sealing assembly isolates external air, preventing contact between air and liquid lead-bismuth, effectively improving the sealing performance during dissolved oxygen concentration detection in liquid lead-bismuth. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an oxygen sensor for liquid metal in one embodiment; Figure 2 This is a cross-sectional view of the first housing in one embodiment; Figure 3 This is a schematic diagram of the second housing in one embodiment; Figure 4 for Figure 1 A schematic diagram of the disassembled liquid metal oxygen sensor. DETAILED DESCRIPTION

[0020] For the purposes of this disclosure, reference will be made to the accompanying drawings which form a part of the disclosure. The drawings are not necessarily to scale of the preferred embodiments of the present disclosure. It is to be understood that the drawings are merely schematic and that actual implementations can differ from the illustrative forms of the disclosure. Rather, the intent is to describe the disclosure in sufficient detail to enable a complete understanding of the disclosure and that the description is not intended to particularly limit the disclosure.

[0021] It is to be understood that the terminology used herein is for the purpose of describing the particular embodiments only and is not intended to be limiting. It is also possible in the present disclosure that dependent claims refer back to a combination of aspects of different independent claims.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description of the disclosure herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The use herein of terms such as "comprising", "including", "having" and the like are specifically intended to be equivalent to the term "consisting of" in order to allow for the inclusion of additional steps, components, etc. without being limited thereto.

[0023] The present disclosure relates to a liquid metal oxygen sensor. In one embodiment, the liquid metal oxygen sensor comprises a protective shell and a sensing structure; the protective shell is used for mounting on an oxygen concentration electrical measurement support, the protective shell has a containing channel and a liquid metal contact hole in communication with each other; the sensing structure comprises a solid electrolyte oxygen probe and a sealing assembly, the solid electrolyte oxygen probe is arranged in the containing channel, part of the solid electrolyte oxygen probe corresponds to the liquid metal contact hole to contact liquid lead bismuth through the liquid metal contact hole, the solid electrolyte oxygen probe is used for electrical connection with the electrical measurement reference end of the oxygen concentration electrical measurement support, and the sealing assembly is connected with the solid electrolyte oxygen probe and abuts against the inner wall of the containing channel to seal the containing channel. Since the first shell and the second shell are detachably connected, that is, the protective shell is detachable, the solid electrolyte oxygen probe can be replaced, the reusability of the liquid metal oxygen sensor is improved, and the cost is reduced. The sealing assembly is additionally arranged between the solid electrolyte oxygen probe and the protective shell, the containing channel is divided into two channels by the sealing assembly, the channel close to the liquid metal contact hole is used for placing the solid electrolyte oxygen probe to form a reference electrode, the contact with the liquid metal is facilitated, the channel close to the liquid metal contact hole is used as a conductive part, the electrical signal sensed by the solid electrolyte oxygen probe is conducted to the electrical measurement reference end of the oxygen concentration electrical measurement support, thereby facilitating accurate measurement of the oxygen concentration in the liquid metal, and the sealing assembly isolates the external air to block the contact between the air and the liquid lead bismuth, thereby effectively improving the sealing performance during detection of the dissolved oxygen concentration in the liquid lead bismuth.

[0024] Please refer to Figure 1 which is a structural schematic diagram of the liquid metal oxygen sensor according to one embodiment of the present disclosure.

[0025] The liquid metal oxygen sensor 10 according to one embodiment comprises a protective shell 100 and a sensing structure 200. The protective shell 100 is used for mounting on an oxygen concentration electrical measurement support, and the protective shell 100 has a containing channel and a liquid metal contact hole 102 in communication with each other. Please refer to Figure 2 The sensing structure 200 comprises a solid electrolyte oxygen probe 210 and a sealing assembly 220. The solid electrolyte oxygen probe 210 is arranged in the containing channel, part of the solid electrolyte oxygen probe 210 corresponds to the liquid metal contact hole 102 to contact liquid lead bismuth through the liquid metal contact hole 102, and the solid electrolyte oxygen probe 210 is used for electrical connection with the electrical measurement reference end of the oxygen concentration electrical measurement support. The sealing assembly 220 is connected with the solid electrolyte oxygen probe 210. Please refer to Figure 2 and Figure 3The protective shell 100 includes a first shell 110 and a second shell 120 which are detachably connected, the first shell 110 has a first channel 104, the second shell 120 has a second channel 106 and the liquid metal contact hole 102 which are in communication with each other, and the first channel 104 and the second channel 106 are in communication to jointly form the accommodation channel; the sealing assembly 220 is arranged in the first channel 104 and abuts against the inner wall of the first shell 110 to seal the accommodation channel, and a part of the solid-state electrolyte oxygen probe 210 is located in the first channel 104 and another part of the solid-state electrolyte oxygen probe 210 is located in the second channel 106 and the liquid metal contact hole 102.

[0026] In the embodiment, the first shell 110 and the second shell 120 are detachably connected, that is, the protective shell 100 is detachable, so that the solid-state electrolyte oxygen probe 210 can be replaced, the reusability of the liquid metal oxygen sensor is improved, and the cost is reduced. The sealing assembly 220 is additionally arranged between the solid-state electrolyte oxygen probe 210 and the protective shell 100, the sealing assembly 220 divides the accommodation channel into two channels, the channel close to the liquid metal contact hole 102 is used for placing the solid-state electrolyte oxygen probe 210 to form a reference electrode, which is convenient for contacting with the liquid metal, and the channel close to the liquid metal contact hole 102 serves as a conductive part, which is convenient for conducting the electrical signal sensed by the solid-state electrolyte oxygen probe 210 to the electrical measurement reference end of the oxygen concentration electrical measurement support, so as to facilitate accurate measurement of the oxygen concentration in the liquid metal, and the sealing assembly 220 isolates the external air to block the contact between the air and the liquid lead bismuth, thereby effectively improving the sealing performance when detecting the dissolved oxygen concentration in the liquid lead bismuth.

[0027] In order to realize accurate control of the oxygen concentration, a liquid metal oxygen sensor with excellent performance is relied on. The existing solid-state oxide (such as zirconium-based ceramic) oxygen sensor can measure very low dissolved oxygen concentration in liquid metal, such as a yttrium-stabilized zirconia (YSZ) solid-state electrolyte Bi / Bi2O3 oxygen sensor. The Bi / Bi2O3 oxygen sensor exhibits good responsiveness in a temperature range of 643 K to 823 K, but the accuracy and repeatability of the Bi / Bi2O3 oxygen sensor are poor due to the low activity of the electrode material. In addition, in a low-temperature environment below 643 K, the output electromotive force (EMF) of the existing oxygen sensor deviates greatly, and the measurement accuracy is low, which is common in some non-air reference electrode oxygen sensors and Bi / Bi2O3 reference electrodes. Among them, the Bi / Bi2O3 reference electrode may cause the solid-state electrolyte to fail due to the internal stress problem caused by expansion at different temperatures.

[0028] In another embodiment, the inner cavity of the solid state electrolyte oxygen probe 210 is filled with 5g to 20g of LSCF powder or LSM powder; and / or, the inner cavity of the solid state electrolyte oxygen probe is plated with a Pt layer of 1cm to 3cm in thickness. In this way, the solid state electrolyte oxygen probe forms a reference electrode with air, LSCF / air, LSM / air and Pt / air as the reference electrode of the oxygen sensor, which has high conductivity and excellent catalytic activity for oxygen reduction reaction, can maintain long-term chemical stability in high temperature environment, has good compatibility between the electrode material and the solid state electrolyte oxygen probe, and has high measurement accuracy of the oxygen sensor in low temperature environment, ensuring high accuracy and long service life of the oxygen sensor in harsh environment, meeting the measurement accuracy and repeatability requirements of the oxygen sensor in different application scenarios.

[0029] In another embodiment, the height of the LSCF powder or LSM powder in the inner cavity of the solid state electrolyte oxygen probe is 5mm to 30mm. The height of the Pt layer on the inner cavity of the solid state electrolyte oxygen probe is 5mm to 30mm. In this way, the solid state electrolyte oxygen probe forms a reference electrode with air, LSCF / air, LSM / air and Pt / air as the reference electrode of the oxygen sensor, which has high conductivity and excellent catalytic activity for oxygen reduction reaction, can maintain long-term chemical stability in high temperature environment, has good compatibility between the electrode material and the solid state electrolyte oxygen probe, and has high measurement accuracy of the oxygen sensor in low temperature environment, ensuring high accuracy and long service life of the oxygen sensor in harsh environment, meeting the measurement accuracy and repeatability requirements of the oxygen sensor in different application scenarios.

[0030] In another embodiment, the method of plating a platinum (Pt) layer inside the solid state electrolyte oxygen probe as a reference electrode is chemical vapor deposition or electrochemical deposition. Chemical vapor deposition forms a platinum thin film by decomposing reaction gas on the surface of the substrate, and is suitable for uniform plating of large area. Electrochemical deposition is a method in which platinum ions are reduced and deposited on the substrate by current in an electrolyte, and is suitable for thin and uniform platinum film, and the equipment is simple. These Pt plating methods have their own advantages, and the choice depends on the specific application requirements, such as film thickness, uniformity, deposition speed, equipment availability and cost, etc. If the Pt layer inside the solid state electrolyte oxygen probe is plated, electrochemical deposition is more commonly used because they have better thin film control ability and adapt to the characteristics of ceramic substrates.

[0031] In one embodiment, please refer to Figure 2The sealing assembly 220 comprises at least two sealing members 222, and the at least two sealing members 222 are sequentially and spacedly connected with the solid electrolyte oxygen probe 210 along the accommodation channel, and each sealing member 222 abuts against the inner wall of the accommodation channel. In this embodiment, the number of the sealing members 222 is at least two, and the sealing members 222 serve as sealing devices of the solid electrolyte oxygen probe 210 in the accommodation channel, so as to fill the gap between the solid electrolyte oxygen probe 210 and the inner wall of the accommodation channel, that is, the inner side of the sealing member 222 abuts against the solid electrolyte oxygen probe 210, while the outer side of the sealing member 222 abuts against the inner wall of the accommodation channel, so that the sealing member 222 blocks the gap between the solid electrolyte oxygen probe 210 and the inner wall of the accommodation channel, thereby making the accommodation channel form at least two mutually isolated channels, one of which is in communication with the liquid metal contact hole 102, and the other of which conducts the electrical signal sensed by the solid electrolyte oxygen probe 210 to the electrical measurement reference end of the oxygen concentration electrical measurement support. Moreover, the at least two sealing members 222 form at least two sealing isolation doors in the accommodation channel, effectively improving the sealing performance of the liquid metal oxygen sensor, and avoiding the liquid lead-bismuth from contacting the external air.

[0032] Further, please refer to Figure 2The sealing member 222 comprises a first high-temperature-resistant fluororubber ring 2222, an iron ring 2224 and a second high-temperature-resistant fluororubber ring 2226 arranged in layers, and the first high-temperature-resistant fluororubber ring 2222, the iron ring 2224 and the second high-temperature-resistant fluororubber ring 2226 are sleeved on the solid-state electrolyte oxygen probe 210. In this embodiment, the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226 are located on both sides of the iron ring 2224, that is, the iron ring 2224 is between the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226, that is, the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226 jointly clamp the iron ring 2224, so that the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226 are arranged in the plane of the iron ring 2224, thereby keeping the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226 flat, and the iron ring 2224 can increase the overall rigidity of the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226, thereby avoiding extrusion deformation of the first high-temperature-resistant fluororubber ring 2222 and the second high-temperature-resistant fluororubber ring 2226. The first high-temperature-resistant fluororubber ring 2222 is sleeved with the solid-state electrolyte oxygen probe 210, and the first high-temperature-resistant fluororubber ring 2222 abuts against one side of the iron ring 2224, thereby enhancing the flat stability of the first high-temperature-resistant fluororubber ring 2222 on the solid-state electrolyte oxygen probe 210. The second high-temperature-resistant fluororubber ring 2226 is sleeved with the solid-state electrolyte oxygen probe 210, and the second high-temperature-resistant fluororubber ring 2226 abuts against the other side of the iron ring 2224, thereby enhancing the flat stability of the second high-temperature-resistant fluororubber ring 2226 on the solid-state electrolyte oxygen probe 210.

[0033] In another embodiment, the first high-temperature-resistant fluororubber ring and the second high-temperature-resistant fluororubber ring have a high-temperature-resistant temperature greater than or equal to 400 DEG C, and the sealing member 222 has better sealing performance than a graphite gasket or a metal gasket.

[0034] In another embodiment, the sealing member further comprises a plurality of sealing silicon grease, and the plurality of sealing silicon grease is connected with the first high-temperature-resistant fluororubber ring and the second high-temperature-resistant fluororubber ring respectively, and the sealing silicon grease abuts against the inner wall of the first shell. The sealing silicon grease is used in cooperation with the first high-temperature-resistant fluororubber ring and the second high-temperature-resistant fluororubber ring to further improve the sealing performance.

[0035] In another embodiment, at least one of the sealing members 222 is located at the end of the solid-state electrolyte oxygen probe 210 away from the liquid metal contact hole 102. In this embodiment, the sealing member 222 serves as a sealing device for the dissolved oxygen concentration test, and the sealing member 222 separates the inner part of the accommodation channel. The sealing member 222 is arranged away from the liquid metal contact hole 102 to avoid the problem of corrosion caused by the contact of the sealing member 222 with liquid lead bismuth, while avoiding affecting the test accuracy of the dissolved oxygen concentration in the liquid lead bismuth.

[0036] In one embodiment, referring to Figure 2 and Figure 3 , the protective shell 100 includes a first shell 110 and a second shell 120 connected in a detachable manner. The first shell 110 has a first channel 104, and the second shell 120 has a second channel 106 and the liquid metal contact hole 102 in communication with each other. The first channel 104 and the second channel 106 are in communication to jointly form the accommodation channel. At least two sealing members 222 are arranged in the first channel 104, and a part of the solid-state electrolyte oxygen probe 210 is located in the first channel 104, and another part of the solid-state electrolyte oxygen probe 210 is located in the second channel 106 and the liquid metal contact hole 102. In this embodiment, the first shell 110 and the second shell 120 are connected in a detachable manner. For example, the first shell 110 and the second shell 120 are screwed, the sealing member 222 is located in the first channel 104 of the first shell 110, and the second shell 120 is screwed to the inner wall of the first channel 104, and the end of the second shell 120 abuts against the sealing member 222. In this way, when the second shell 120 is screwed and assembled with the first shell 110, the second shell 120 presses the sealing member 222 tightly, so that the sealing member 222 abuts against the inner wall of the first channel 104 more tightly, thereby further improving the sealing performance of the solid-state electrolyte oxygen probe 210 in the protective shell 100. The screwing of the first shell 110 and the second shell 120 not only allows the solid-state electrolyte oxygen probe 210 to be disassembled and maintained, thereby facilitating the timely replacement of the solid-state electrolyte oxygen probe 210, but also allows the sealing member 222 to be pressed tightly in the first channel 104 through screwing, thereby achieving the effect of additional sealing.

[0037] Further, referring to Figure 2The protective shell 100 further comprises a sealing pipe 130 connected with the first shell 110, the sealing pipe 130 is located in the first channel 104, the inside of the sealing pipe 130 is communicated with the first channel 104, at least one sealing member 222 is arranged in the sealing pipe 130, and at least one sealing member 222 is abutted against the end of the sealing pipe 130 close to the liquid metal contact hole 102. In the embodiment, the sealing pipe 130 is arranged in the first shell 110, that is, the sealing pipe 130 is arranged in the first channel 104. The sealing pipe 130 is used as a mounting limiting pipe of the sealing member 222, at least one sealing member 222 is arranged in the sealing pipe 130, and part of the sealing member 222 is fixedly mounted. At least one sealing member 222 is further abutted against the outside of the sealing pipe 130, the sealing pipe 130 and the second shell 120 jointly hold at least one sealing member 222, and part of the sealing member 222 is extruded by the sealing pipe 130 and the second shell 120, so that the sealing member 222 is tightly pressed in the first channel 104, thereby improving the sealing performance of the liquid metal oxygen sensor.

[0038] In another embodiment, the first shell 110 is integrally formed with the sealing pipe 130, so that the first shell 110 is firmly connected with the sealing pipe 130, and the structure of the oxygen sensor is more compact.

[0039] Further, please refer to Figure 2The sealing pipe 130 comprises a pipe body 132 and a limiting pipe 134. The pipe body 132 is connected with the inner wall of the first channel 104, and the limiting pipe 134 is connected with the inner wall of the pipe body 132. At least one sealing member 222 is abutted against one end of the limiting pipe 134 close to the liquid metal contact hole 102. In this embodiment, the pipe body 132 is fixed on the inner wall of the first channel 104, and the limiting pipe 134 is a hollow pipe. The inside of the limiting pipe 134 is communicated with the first channel 104. The limiting pipe 134 is connected with the inner wall of the pipe body 132 to form a stepped structure together, that is, the limiting pipe 134 forms a limiting step at one end close to the liquid metal contact hole 102. The limiting pipe 134 is abutted against the sealing member 222. The limiting step limits the sealing member 222 in the first channel 104, avoiding the sealing member 222 from separating from the solid electrolytic oxygen probe 210. The inner wall of the pipe body 132 communicated with the first channel 104 also forms a stepped structure, that is, the pipe body 132 forms another limiting step at one end close to the liquid metal contact hole 102. The one end of the pipe body 132 close to the liquid metal contact hole 102 is used to abut against at least one sealing member 222, so that the second shell 120 and the pipe body 132 extrude the sealing member 222 together, also avoiding the sealing member 222 from separating from the solid electrolytic oxygen probe 210.

[0040] In another embodiment, the number of sealing members 222 is two, one of which is abutted against the limiting pipe 134, and the other is abutted against the pipe body 132. The diameter of the sealing member 222 abutted against the limiting pipe 134 is smaller than that of the sealing member 222 abutted against the pipe body 132, avoiding the situation of air leakage between the solid electrolytic oxygen probe 210 and the inner wall of the sealing pipe 130, so that the solid electrolytic oxygen probe 210 is reliably connected to the sealing pipe 130 by the sealing assembly 220.

[0041] In another embodiment, the pipe body 132 and the limiting pipe 134 are integrally formed, so that the pipe body 132 and the limiting pipe 134 are firmly connected, improving the compactness of the sealing pipe 130.

[0042] In one of the embodiments, please refer to Figure 1The sensing structure 200 further comprises a fastening nut 230, which is located in the accommodating channel and is screwed with the protective shell 100. The fastening nut 230 is in contact with the solid-state electrolyte oxygen probe 210 in liquid state, and the part of the fastening nut 230 in contact with the solid-state electrolyte oxygen probe 210 is exposed to the liquid metal contact hole 102. In this embodiment, the fastening nut 230 is located at the position of the liquid metal contact hole 102 of the protective shell 100, and the fastening nut 230 is screwed with the protective shell 100. Part of the fastening nut 230 is located in the accommodating channel. During the screwing process, the fastening nut 230 presses the solid-state electrolyte oxygen probe 210, and the fastening nut 230 tightly presses the sealing member 222 in the accommodating channel, forming an additional secondary seal, and the sealing performance of the liquid metal oxygen sensor is further improved.

[0043] In another embodiment, the number of liquid metal contact holes 102 on the protective shell 100 is multiple, and the multiple liquid metal contact holes 102 are uniformly distributed on the protective shell 100, so that the protective shell 100 is in a hollow structure at the position where the fastening nut 230 is in contact with the solid-state electrolyte oxygen probe 210, facilitating the full contact of the solid-state electrolyte oxygen probe 210 with liquid lead-bismuth.

[0044] In another embodiment, the opening area of the liquid metal contact hole is smaller than the axial cross-sectional area of the solid-state electrolyte oxygen probe at the liquid metal contact hole. The liquid metal contact hole is small, for example, the liquid metal contact hole is a slit-shaped through hole, so that the solid-state electrolyte oxygen probe can be protected and the fragments of the solid-state electrolyte oxygen probe after fragmentation can be prevented from entering the liquid lead-bismuth under the condition of oxygen measurement.

[0045] In one of the embodiments, please refer to Figure 4The liquid metal oxygen sensor 10 further comprises electrode wires 300, a mounting flange 400, a flange 500, and heat dissipation fins (not shown in the figure). The electrode wires 300 are arranged in the accommodating channel, and are connected to the solid-state electrolyte oxygen probe 210 and the flange 500 respectively. The mounting flange 400 is sleeved on the outer wall of the protective shell 100, and part of the flange 500 is clamped in the accommodating channel. The mounting flange 400 and the flange 500 are located at the end of the protective shell 100 away from the liquid metal contact hole 102. The mounting flange 400 and the flange 500 are used for being fixed on an oxygen concentration electrical measurement support, and the flange 500 is further used for being electrically connected to an electrical measurement reference end of the oxygen concentration electrical measurement support. The heat dissipation fins are located between the mounting flange and the flange 500, and are connected to the outer wall of the protective shell. In this embodiment, the electrode wires 300 conduct the solid-state electrolyte oxygen probe 210 and the flange 500, so that the potential signal generated by the solid-state electrolyte oxygen probe 210 after contacting with liquid lead bismuth is transmitted to the electrical measurement reference end of the oxygen concentration electrical measurement support in time, thereby facilitating accurate measurement of the dissolved oxygen concentration in the liquid lead bismuth. The mounting flange 400 and the flange 500 serve as a mounting and fixing flange assembly of the liquid metal oxygen sensor. In addition to serving as an electrically conductive component, the flange 500 facilitates mounting of the liquid metal oxygen sensor on the oxygen concentration electrical measurement support. The heat dissipation fins conduct heat away from the protective shell, thereby reducing the temperature of the protective shell, and avoiding damage of the liquid metal oxygen sensor due to overheating when contacting with liquid lead bismuth. In this way, in combination of the heat dissipation fins, the first high-temperature-resistant fluororubber ring, and the second high-temperature-resistant fluororubber ring, the liquid metal oxygen sensor can accurately, stably, and leaklessly measure the oxygen concentration in liquid lead bismuth at 200-700℃.

[0046] In another embodiment, the solid-state electrolyte oxygen probe has an inner cavity, and the opening of the inner cavity faces the flange. The inner cavity is used for adding LSCF powder or LSM powder, or plating a Pt layer on the peripheral wall of the inner cavity.

[0047] In one of the embodiments, please refer to Figure 4The protective shell 100 is provided with a gas permeable hole 108 in communication with the accommodation channel, and the gas permeable hole 108 is located at the end of the protective shell 100 away from the liquid metal contact hole 102. In this embodiment, the gas permeable hole 108 is arranged away from the liquid metal contact hole 102, and specifically, the gas permeable hole 108 is arranged symmetrically with the liquid metal contact hole 102 with the sealing member 222 as the center, and the sealing member 222 divides the accommodation channel into two channels, one of which is in communication with the liquid metal contact hole 102, and the other of which is in communication with the gas permeable hole 108.

[0048] In one embodiment, the present disclosure also provides a preparation method of a solid-state electrolyte ceramic for the solid-state electrolyte oxygen probe of the liquid metal oxygen sensor in any of the above embodiments, the preparation method comprising: S101, preparing yttrium-stabilized zirconia powder in a preset proportion according to the molar ratio of yttrium oxide and zirconia, wherein the doping amount of yttrium oxide is 3 mol% to 8 mol%; S103, mixing the yttrium-stabilized zirconia powder with an organic solvent in a preset mass ratio, and performing ball milling treatment to obtain a uniform slurry, wherein the organic solvent comprises ethanol; further, the preset mass ratio of the organic solvent is 5%wt to 20%wt.

[0049] S105, using an injection molding technique to inject the slurry into a mold through a blind pipe mold, and performing dehydration treatment at room temperature to form a green body; S107, performing pre-sintering treatment on the green body to remove organic matter and enhance the mechanical strength of the green body; wherein the pre-sintering treatment temperature is 600°C to 800°C, and the pre-sintering treatment time is 2 hours to 4 hours, so as to more completely remove the organic matter and enhance the mechanical strength of the green body; S109, performing sintering treatment on the pre-sintered green body to obtain a dense blind pipe-shaped ceramic structure; wherein the sintering temperature is 1400°C to 1600°C, and the sintering time is 4 to 6 hours; S111, performing surface polishing, cutting and surface treatment on the sintered blind pipe-shaped ceramic to obtain a solid-state electrolyte ceramic; wherein the outer diameter of the solid-state electrolyte ceramic is 5 mm to 20 mm, and the wall thickness of the solid-state electrolyte ceramic is 1 mm to 5 mm.

[0050] In this embodiment, the preparation process can ensure that the final product has good electrochemical performance and mechanical strength, and is suitable for high-temperature application fields such as liquid metal oxygen sensors.

[0051] The present disclosure also provides a manufacturing method of a liquid metal oxygen sensor, comprising the following steps: A solid electrolyte oxygen probe is provided; A reaction catalyst is formed in the inner cavity of the detection end of the solid electrolyte oxygen probe; in this embodiment, the reaction catalyst is filled in the inner cavity of the detection end of the solid electrolyte oxygen probe. For example, the reaction catalyst is at least one of LSCF powder or LSM powder. In other embodiments, the reaction catalyst is not limited to being filled in the inner cavity of the detection end of the solid electrolyte oxygen probe. For example, the reaction catalyst is a Pt layer, and the reaction catalyst is formed on the inner cavity wall of the detection end of the solid electrolyte oxygen probe by an electroplating process.

[0052] A sealing assembly is installed in the first channel of the first shell to seal the accommodation channel; in this embodiment, since the sealing assembly is pre-installed in the first shell, a sealed space is formed inside the accommodation channel.

[0053] The solid electrolyte oxygen probe is installed in the first channel and connected with the sealing assembly; in this embodiment, after the solid electrolyte oxygen probe is installed in the first shell, the sealing assembly seals the inside of the first shell, achieving the first sealing of the solid electrolyte oxygen probe.

[0054] The second shell is detachably connected to the first shell, and the part of the solid electrolyte oxygen probe outside the first shell is inserted into the second shell, so that part of the solid electrolyte oxygen probe is located in the first channel, and another part of the solid electrolyte oxygen probe is located in the second channel and the liquid metal contact hole; in this embodiment, after the second shell is assembled with the first shell, the second shell extrudes the sealing assembly to the inner wall of the first shell, so that the sealing of the solid electrolyte oxygen probe by the sealing assembly is more tight, achieving the second sealing of the solid electrolyte oxygen probe.

[0055] The fastening nut is installed in the second shell and extrudes one end of the solid electrolyte oxygen probe adjacent to the liquid metal contact hole; in this embodiment, the fastening nut is installed from the second shell, and the fastening nut extrudes one end of the solid electrolyte oxygen probe away from the sealing assembly, so that the sealing of the solid electrolyte oxygen probe by the sealing assembly is further tight, achieving the third sealing of the solid electrolyte oxygen probe.

[0056] The electrode lead is installed in the inner cavity of the solid electrolyte oxygen probe through the first channel, and one end of the electrode lead is inserted into the inner cavity of the solid electrolyte oxygen probe at the detection end. In this embodiment, the inner cavity of the solid electrolyte oxygen probe is provided with a reaction catalyst for catalyzing the reaction, and part of the electrode lead is also located in the inner cavity of the solid electrolyte oxygen probe, so that the electrode lead contacts the reaction catalyst, facilitating the collection of the reaction voltage for detecting the liquid lead-bismuth oxygen concentration.

[0057] In this way, under the three sealing effects, the sealing performance of the solid-state electrolyte oxygen probe in the protective shell is improved, so that the sealing performance when detecting the dissolved oxygen concentration in the liquid lead bismuth is improved. Moreover, the first shell and the second shell are assembled separately, the detachable connection of the first shell and the second shell is realized, so as to facilitate the replacement of the solid-state electrolyte oxygen probe, improve the reusability of the oxygen sensor for liquid metal, and reduce the cost.

[0058] The above-described embodiments only express several implementation manners of the present disclosure, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the present disclosure, several modifications and improvements can be made, which all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure should be subject to the appended claims.

Claims

1. An oxygen sensor for liquid metal, characterized in that, include: A protective housing for mounting on an oxygen concentration electrical measuring bracket, the protective housing having interconnected receiving channels and liquid metal contact holes; The sensing structure includes a solid electrolyte oxygen probe and a sealing assembly. The solid electrolyte oxygen probe is disposed within the accommodating channel, and a portion of the solid electrolyte oxygen probe corresponds to the liquid metal contact hole to contact liquid lead bismuth through the liquid metal contact hole. The solid electrolyte oxygen probe is used to electrically connect to the electrical reference terminal of the oxygen concentration electrical measuring bracket. The sealing assembly is connected to the solid electrolyte oxygen probe. The protective housing includes a detachably connected first housing and a second housing. The first housing has a first channel, and the second housing has a second channel that communicates with each other and the liquid metal contact hole. The first channel and the second channel together form the receiving channel. The sealing assembly is disposed within the first channel and abuts against the inner wall of the first housing to seal the accommodating channel. A portion of the solid electrolyte oxygen probe is located within the first channel, and another portion of the solid electrolyte oxygen probe is located within the second channel and the liquid metal contact hole.

2. The oxygen sensor for liquid metal according to claim 1, characterized in that, The sealing assembly includes at least two seals, which are sequentially and spaced apart from each other along the receiving channel and are connected to the solid electrolyte oxygen probe. Each seal abuts against the inner wall of the receiving channel.

3. The oxygen sensor for liquid metal according to claim 2, characterized in that, The sealing element includes a first high-temperature resistant fluororubber ring, an iron ring, and a second high-temperature resistant fluororubber ring stacked together. The first high-temperature resistant fluororubber ring, the iron ring, and the second high-temperature resistant fluororubber ring are all sleeved on the solid electrolyte oxygen probe. The high-temperature resistant temperature of the first high-temperature resistant fluororubber ring and the second high-temperature resistant fluororubber ring is greater than or equal to 400°C. And / or, the liquid metal oxygen sensor further includes heat dissipation fins, which are connected to the outer wall of the protective shell. And / or, the sealing element is located at the end of the solid electrolyte oxygen probe away from the liquid metal contact hole.

4. The oxygen sensor for liquid metal according to claim 2, characterized in that, The protective housing also includes a sealing pipe connected to the first housing. The sealing pipe is located inside the first channel and its interior communicates with the first channel. At least one of the sealing elements is provided inside the sealing pipe, and at least one of the sealing elements abuts against one end of the sealing pipe near the liquid metal contact hole.

5. The oxygen sensor for liquid metal according to claim 4, characterized in that, The sealed conduit includes a conduit body and a limiting tube. The conduit body is connected to the inner wall of the first channel, and the limiting tube is connected to the inner wall of the conduit body. At least one of the sealing elements is abutted at one end of the limiting tube near the liquid metal contact hole.

6. The oxygen sensor for liquid metal according to claim 1, characterized in that, The sensing structure further includes a fastening nut screwed to the protective housing, the fastening nut passing through the receiving channel, the fastening nut corresponding to the liquid metal contact hole, the fastening nut abutting against the solid electrolyte oxygen probe; and / or, the opening area of ​​the liquid metal contact hole is smaller than the axial cross-sectional area of ​​the solid electrolyte oxygen probe at the liquid metal contact hole.

7. The oxygen sensor for liquid metal according to claim 1, characterized in that, The liquid metal oxygen sensor further includes electrode wires, a mounting flange, and a flanged portion. The electrode wires are disposed within the accommodating channel and are connected to the solid electrolyte oxygen probe and the flanged portion, respectively. The mounting flange is fitted onto the outer wall of the protective housing, and the flanged portion is secured within the accommodating channel. The mounting flange and the flanged portion are located at the end of the protective housing away from the liquid metal contact hole. The mounting flange and the flanged portion are used to fix the sensor to the oxygen concentration electrical measuring bracket, and the flanged portion is also used to electrically connect to the electrical measuring reference terminal of the oxygen concentration electrical measuring bracket.

8. The oxygen sensor for liquid metal according to claim 1, characterized in that, The protective housing has a vent hole that communicates with the receiving channel, and the vent hole is located at the end of the protective housing away from the liquid metal contact hole.

9. The oxygen sensor for liquid metal according to claim 1, characterized in that, The solid electrolyte oxygen probe is filled with 5g to 20g of LSCF powder or LSM powder; and / or, the inner wall of the solid electrolyte oxygen probe is electroplated with a Pt layer with a thickness of 1cm to 3cm.

10. A method for manufacturing an oxygen sensor for liquid metal, characterized in that, include: Provides solid electrolyte oxygen probes; The reactive catalyst is formed in the inner cavity of the detection end of the solid electrolyte oxygen probe; The sealing assembly is installed in the first channel of the first housing to seal the receiving channel; The solid electrolyte oxygen probe is inserted into the first channel and connected to the sealing assembly; The second housing is detachably connected to the first housing, and the portion of the solid electrolyte oxygen probe located outside the first housing is inserted into the second housing, such that a portion of the solid electrolyte oxygen probe is located in the first channel, and the other portion of the solid electrolyte oxygen probe is located in the second channel and the liquid metal contact hole. Insert the fastening nut into the second housing and press the end of the solid electrolyte oxygen probe adjacent to the liquid metal contact hole; The electrode wire is inserted into the inner cavity of the solid electrolyte oxygen probe through the first channel, and one end of the electrode wire is inserted into the inner cavity of the solid electrolyte oxygen probe at the detection end.

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